Hammer mfg



T. E. BARNUM. IELECTRIC SWITCH.

APPLlcAloN mso uov.21, wos;

Patented Aug. 8, 1916.

4 SHEETS-SHEET l- -Ww mw l I., E. BAnNuM. ELECTRIC SWITCH. APPLICATION FILEDl NOV. 2| |908.

1,1 93,660. Patented Aug. 8,1916.

4 SHEETS-SHEET 2 @ZT/765535 7X2;

T. E. BARNUM.

ELECTRIC SWITCH.

APPLICATION FILED NOV. 2l, 1908.

1,193,660. Patented Aug. 8,1916.

4 SHEETS-SHEET 3.

y 5%@ Mfg T. E. BARNUM.

ELECTRIC SWITCH.

APPLlcATloN FILED Nov. 21. 190B.

1,1 93,660. Patented Aug. 8, 1916.

4 SHEETS-SHEET 4.

UNITED sTATs PATENT OFFICE.

THOMAS E. BARNUM, OF MILWAUKEE, WISCONSIN, ASSIGNOR TO THE CUTLER- HAMMER MFG. CO., OF MILWAUKEE, WISCONSIN, A CORPORATION OF WIS- CONSIN.

ELECTRIC SWITCH.

Specification of Letters Patent.

Patented Aug. 8, y1916.

To aZZwwm it may concern:

` Be it known that I, THOMAS E. BARNUM, a citizen of the United States, residing at Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented new and useful Improvements in Electric Switches, of which the following is a full, clear, concise, and exact description, reference being vhad to the accompanying drawing, forming a part of this specification.

My invention relates to improvements in electric switches, and more particularly to those which are .electromagnetically operated.

One object of my invention is to provide a switch which willbe simple in construction, durable and efficient in operation.

Other objects and advantages of my invention will be hereinafter set forth.

For the purpose of more fully disclosing; my invention, I have illustrated, in the accompanying drawings, one form thereof which I have worked out in practice. Of course my invention is susceptible of various modifications. A

Figure 1 is a front elevation of the device; Fig. 2 is a side elevation thereof; Fig. 3 is a vertical sectional view taken on line 3-3, Fig. 1, and Figs. 4, 5, 6, 7 and 8, are detail views of parts of the device'I formed of stamped metal. I

The several parts of the switch are preferably mounted on an insulating base 1. Secured to the base 1 by bolts 3' and 4 is a frame 2. The bolt 4, as will be hereinafter explained, forms one terminal of the switch and is, therefore, preferably formed of brass, and provided with a binding-nut 5. Extending outwardly from the lower part of the frame 2 are two substantiallyparallel arms 6, through the ends of which extend a pin 7. T he pin 7 is held in placel by cotter-pins 7 a, provided at opposite ends thereof. Fulcrumed on the pin 7 is a switch member 8, which is preferably'made broad and flat at'l its lower end, and provided with angularly disposed extensions 9 through which'passes the pin 7. The extensions 9- are preferably arranged to engage a projection 10, provided-on the frame 2, to limit the outward movement of the switch member 8. A spring 11 surrounding the pin 7 has one end thereof secured to the projec-V tion 10, while its opposite end bears against the switch member 8 and tends' to force the forms a binding post.

switch member outwardly. Secured tothe frame 2, by a screw 12, is a core 13 of an. electromagnet 14. The head of the screw 12 is preferably counter sunk in the end of the core 13. The winding 14 surrounds the core 13 and is retained thereon by means of insulating disks 15, which are fitted onto the ends of the core 13. The ends of the core 13 are preferably formed of reduced di-y ameter so as to form shoulders against which the disks 15 are adapted to bear. The disks 15 may be retained in position by flattening the ends of the core. Projecting outwardly from the upper end of the frame 2 are a pair of horns 16, arranged substantially parallel to the axis of the winding `14. The horns 16 preferably project beyond the magnet 14 for the purpose hereinafter set forth. Secured to the base 1 by means of a bolt 18, is a contact holder or support 19. In order to prevent the member 19 from turning, the

same is preferablyy additionally secured to the base by a screw 20. The member 19 is preferably of the shape shown, being provided at its outer end with a portion adapted to receive a wedge-shaped carbon contact block 21.' The contact 21 isl held in place by means of a clamping member 22, which is secured to the member 19 by means of a screw 23. On its under side the member 19 is preferably recessed to receive one the base 1 and carries two nuts 31 and 32.

The nut 32 is adapted to be turned against the rear of the base to hold lthe terminal lock 29 in position. The end of the stem The blow-out coil 28'is preferably formed of a heavy copper strip, and is self supporting. Extending through the bl-ow-out coil 28 is a core 33. Secured to the ends of the core 33, by screws 34, are a pair of pole pieces 35, which are provided with polar faces 36 disposed on opposite sides of the carbon contact 21. The

-core 33 is adapted to turn in the blow-out coil, whereby the pole pieces may be raised to the' position illustrated in Fig. 3, to give access to the carbon contact. One of the pole pieces is provided with an extension 37, adapted to bear against the base 1 to limit the downward movement thereof. Interposed between the ends of the blow-out coil and the pole pieces are insulating disks 38. Inter-posed between the polar faces 36 is an insulating chute or barrier 40, which is supported by bolts 41 passing through said polar faces. The insulating chute 40 shields the arcing contacts from the polar faces.

Adjacent to its upper end the switch member 8 is provided with a bifurcated projection 42, adapted to receive one end of an auxiliary contact member 43, which is fulcrumed 'on a pin 44 passing through the bifurcations of the projection 42. At its upper end the member 43 carries an arcing contact 45, adapted to engage the carbon contact. 21. The arcing Contact 45 is preferably formed of an angle plate, and is secured to the member 43 by means of screws 46. The member 43 is provided with a tail piece 47. Interposed between the tail piece 47 and the arm 8 is a coil spring 48, which tends to throw the upper end of the member 43 inwardly against the upper end of the switch member 8, which forms a stop therefor. Secured to the inner side of the switch member 8, by screws 49, is a contact plate 50, adapted to engage the main contact 24. Interposed between the contact 50 and the arm 8 is a conducting strip 51, having a flexible extension, which passes through an aperture in the arm 8 and downwardly on the outside thereof to the terminal 5, to which it is secured. The flexible conducting strip 51 is secured to the outside of the arm 8 by means of a screw 54. The screw 54 also electrically connects one end of a flexible conductor 55 to the conducting strip 54. The conductor 55 passes upwardly over the pin 44, and has its opposite end electrically connected to the arm 43. Adjacent to the outer end of the core 13 of the magnet 14 the arm 8 is provided with a projection 56. T`he arm 8 forms the armature ofthe magnet 14, and hence, when said mag net is energized, said arm is drawn inwardly until the projection 56 thereon engages the end of the core 13. and the contact plate 49 engages the ends of the horns 16. This results in completing a plurality of magnetic circuits for the magnet 14, and hence the arm 8 is firmly held in its innermost position.

As the arm 8 is drawn inwardly, the arcing contact 45 first engages the carbon contact 21, and inasmuch as the member 43 which carries the areing contact, is pivoted to the arm 8 a rubbing action between the two arcing contacts is produced. This keeps the contacts clean and insures a good electrical contact between the same. As the arm 8 is still farther drawn inwardly, the contact plate 49 is moved into engagement with the end of the main contact brush 24.

The magnetic circuits for the magnet 14 extend from one end( of the core through the frame 2, through the horns 16, and through 'extensions 6 to the contact member, and thence to the other end of the core. It will thus be seen that a strong pull is exerted on the switch member and that the magnetic attraction is gradually increased as the switch member moves inwardly. This causes the switch to close with the desired force.

The switch arm may be provided with a pair of lateral projections 57, adapted to engage and bridge a pair of auxiliary contacts 58 mounted on the base 1. Each of the auxiliary contacts preferably compris/es a cylindrical member, provided at one end with an extension 59, of a reduced diameter, and at its other end with a screwthreaded stem 60 passing through the base 1. The stem 60 carries a nut 61, adapted to bear against the base to hold the contact in position. Suitably secured to each of the auxiliary contacts and surrounding the extension thereon, is a coiled spring 62. At their ends the springs 62 are provided with contacts 63, adapted to be engaged by the extensions 57 of the main switch 8. The springs 62 form part of the auxiliary contacts and are of suiicient length to be engaged by the switch member before the same engages the main contact.

The several parts of the device shown in Figs. l to 3 inclusive, are preferably formed of cast metal. The same may, however, be formed of sheet-metal, as shown in Figs. 4 to 7, inclusive. Fig. 4 shows a frame corresponding to the frame 2 in Figs. 1 to 3 inelusive. This frame is stamped from a single sheet of met-al, the arms and the horns 71 corresponding to the arms 6 and horns 16 of the frame 8, being formed by extensions bent perpendicularly to the main portion thereof. In this structure in lieu of the projection 10, for limiting the outward movement of the switch member, I .provide the arms 70 with projections 72 against which the lower edge of the switch member is adapted to strike.

The switch member illustrated in Fig. 5 is of substantially the same shape as the switch member 8 shown in Figs. 1 to 3, but is stamped from sheet-metal. The lower edge 73 of the switch member is curved inwardly to engage the projections 72 to limit the outward movement thereof. Formed integrally with the switch member and extending from the lower edge thereof are a pair of extensions 74, only one of which is shown. The extensions 74 are so arranged as to fit between the arms 70 and are curved to form rings to receive the pin upon which the switcharm is fulcrumed. The arcing contact arm is adapted to be fulcrumed on a pin passing through ears 75. The ends of the ears 75 pass through the switch member and are clenched on the inside thereof, while shoulders 76 engage the front between the side pieces and is held in placel by means of a screw 80, which passes through an extension 81. The extension 81 is reinforced by the ends of the side pieces which are bent back thereon.

Fig. 7 illustrates one of the` pole pieces stamped from a single sheet of metal.

Fig. 8 illustrates a bracket 83 stamped from sheet metal and provided with a pair of forwardly extending arms 84. This bracket is adapted to be secured to the insulating base for supporting the blow-out coil if desired.

What I claim asnew and desire to secure by Letters Patent is 1. In a magnetic switch, in combination, a magnetic frame, an electromagnetic winding thereon, a compound switch element comprising two rigid `members, one pivoted to said frame and arranged in front of said winding to be attracted thereby and the other pivoted on the front face of the former at a point removed from the free end thereof and having its free extremity extending therebeyond and biased toward said former member, a contact mounted on the free end of each of' said members, av

rigid contact holden-'a main laminated contact and an arcing contact carried by said holder for respective engagement by the aforesaid contacts, said laminated contact being inclined toward the pivot of said element. ,Y

2. In an electromagnetic switch, in combination, a magnet frame, yan electromagnetic winding mounted thereon, said frame having a magnetic extension paralleling the axis of said winding, a compound switch element comprising two rigid members, one,

pivoted to said frame and arranged in front of said winding to be attracted thereby t0- ward said magnetic extension of said frame and the other of said members being pivoted on the front face of the former at a point removed from the free end thereof and having its free extremity extending therebeyond and biased toward said former member, a contact mounted on the free end of each of said members, a rigid contact holder, a main laminated contact and an arcing contact carried by said holder for respective engagement by the aforesaid contacts, said laminated contact being inclined toward' the pivot of said element.

3. A magnet frame for electric switches formed of sheet metal and comprising a main portion provided adjacent to one end, with a pair of lateral extensions bent substantially at right angles thereto for supporting a switch member, said main portion being also provided with a pair of obliquely disposed extensions bent substantially at right angles thereto and adapted to provide magnetic paths for the magnetcarried by said frame.

4. A contact memberpfor electric switches, formed of sheet metal and comprising an elongated main portion provided adjacent to one end with extensions adapted to sup- Qport said main portion on a suitable pivot, said main portion being provided adjacent to its opposite end with a pairlof lugs disposed substantially perpendicular y thereto for supporting an auxiliary switch member.

5. A contact holder for electric switches formed of sheet metal and having an inclined portion for receiving a laminated main contact, and a portion disposed substantially at right angles to said inclined portion for receiving a carbon contact.

6. A contact holder for electric switches, formed of sheet metal and comprising a main inclined portion having angularly disposed-side pieces, said inclined portion being adapted to support a main contact, and having an angularly disposed extension for su porting a carbon contact.

n witness whereof, I have hereunto sublscribed my name in the presence of two witnesses.

` THOMAS E. BARNUM. Witnesses:

FRAM; H. HUBBARD. S. WJFiTz GERALD. 

